With the growth in the optical communication and many other optical applications, optical elements alignment has become the focus of much industrial attention. This is a key production process because the connection efficiency of the optical elements greatly influences the overall production rates and the quality of the connected optical elements for the products used in optical communication.
Metallic wire connection is relatively easy because an electric current will flow as long as the two wires are in contact. The connection between two optical elements, such as connections of an optical fiber to a photo diode, or connection of one optical fiber to one optical waveguide, it needs to align two optical elements. However, requires much greater precision, in the order of sub-micro-meters. Therefore, experienced technicians are needed for optical elements alignment, but as such technicians are limited in supply, this causes a bottleneck to the mass production of components for optical communications.
Automatic alignment system can shift slightly the light axes of two optical elements, such as optical fibers to minimize transmission loss. Once alignment is complete, the light axes are fixed by laser processing or a setting resin.
For precisely aligning two optical elements, the applicant of the present invention discloses an invention “Nanomover For Optical Element Alignment Without Driving Electrically”, which is allowed with a patent in U.S. with a U.S. Pat. No. 7,817,890 B2 (which also allows with patent rights in China, Taiwan, Japan and Germany). In this patent, the applicant disclosed a device for aligning two optical elements by using a weak spring and a strong spring, which is achieved mechanically without any electric elements. However, in case the two elements separate with a larger distance over a largest traveling length of the nanomover, the nanomover of this prior art is not suitable for the alignment operation.
There are many kinds of micromovers in the prior arts for coarsely adjusting the optical elements in alignment operation so as to drive them to a desire position. However, each traveling step of the micromover is too large to match the requirement in optical alignment.
Therefore, the inventor of the present invention tries to combine the advantages of the nanomover in U.S. Pat. No. 7,817,890 B2 and the prior art micromover so as to have a precise adjustment in optical alignment. Furthermore, the height, volume, weight and cost of the whole structure are improved.